Re: [PATCH V6 16/21] soc/tegra: pmc: Add pmc wake support for tegra210

Dmitry Osipenko
2019-07-23T01:08:34Z

23.07.2019 3:58, Dmitry Osipenko пишет:
> 21.07.2019 22:40, Sowjanya Komatineni пишет:
>> This patch implements PMC wakeup sequence for Tegra210 and defines
>> common used RTC alarm wake event.
>>
>> Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
>> ---
>> drivers/soc/tegra/pmc.c | 111 ++++++++++++++++++++++++++++++++++++++++++++++++
>> 1 file changed, 111 insertions(+)
>>
>> diff --git a/drivers/soc/tegra/pmc.c b/drivers/soc/tegra/pmc.c
>> index 91c84d0e66ae..c556f38874e1 100644
>> --- a/drivers/soc/tegra/pmc.c
>> +++ b/drivers/soc/tegra/pmc.c
>> @@ -57,6 +57,12 @@
>> #define PMC_CNTRL_SYSCLK_OE BIT(11) /* system clock enable */
>> #define PMC_CNTRL_SYSCLK_POLARITY BIT(10) /* sys clk polarity */
>> #define PMC_CNTRL_MAIN_RST BIT(4)
>> +#define PMC_CNTRL_LATCH_WAKEUPS BIT(5)

Please follow the TRM's bits naming.

PMC_CNTRL_LATCHWAKE_EN

>> +#define PMC_WAKE_MASK 0x0c
>> +#define PMC_WAKE_LEVEL 0x10
>> +#define PMC_WAKE_STATUS 0x14
>> +#define PMC_SW_WAKE_STATUS 0x18
>>
>> #define DPD_SAMPLE 0x020
>> #define DPD_SAMPLE_ENABLE BIT(0)
>> @@ -87,6 +93,11 @@
>>
>> #define PMC_SCRATCH41 0x140
>>
>> +#define PMC_WAKE2_MASK 0x160
>> +#define PMC_WAKE2_LEVEL 0x164
>> +#define PMC_WAKE2_STATUS 0x168
>> +#define PMC_SW_WAKE2_STATUS 0x16c
>> +
>> #define PMC_SENSOR_CTRL 0x1b0
>> #define PMC_SENSOR_CTRL_SCRATCH_WRITE BIT(2)
>> #define PMC_SENSOR_CTRL_ENABLE_RST BIT(1)
>> @@ -1922,6 +1933,55 @@ static const struct irq_domain_ops tegra_pmc_irq_domain_ops = {
>> .alloc = tegra_pmc_irq_alloc,
>> };
>>
>> +static int tegra210_pmc_irq_set_wake(struct irq_data *data, unsigned int on)
>> +{
>> + struct tegra_pmc *pmc = irq_data_get_irq_chip_data(data);
>> + unsigned int offset, bit;
>> + u32 value;
>> +
>> + if (data->hwirq == ULONG_MAX)
>> + return 0;
>> +
>> + offset = data->hwirq / 32;
>> + bit = data->hwirq % 32;
>> +
>> + /*
>> + * Latch wakeups to SW_WAKE_STATUS register to capture events
>> + * that would not make it into wakeup event register during LP0 exit.
>> + */
>> + value = tegra_pmc_readl(pmc, PMC_CNTRL);
>> + value |= PMC_CNTRL_LATCH_WAKEUPS;
>> + tegra_pmc_writel(pmc, value, PMC_CNTRL);
>> + udelay(120);
>
> Why it takes so much time to latch the values? Shouldn't some status-bit
> be polled for the completion of latching?
>
> Is this register-write really getting buffered in the PMC?
>
>> + value &= ~PMC_CNTRL_LATCH_WAKEUPS;
>> + tegra_pmc_writel(pmc, value, PMC_CNTRL);
>> + udelay(120);
>
> 120 usecs to remove latching, really?
>
>> + tegra_pmc_writel(pmc, 0, PMC_SW_WAKE_STATUS);
>> + tegra_pmc_writel(pmc, 0, PMC_SW_WAKE2_STATUS);
>> +
>> + tegra_pmc_writel(pmc, 0, PMC_WAKE_STATUS);
>> + tegra_pmc_writel(pmc, 0, PMC_WAKE2_STATUS);
>> +
>> + /* enable PMC wake */
>> + if (data->hwirq >= 32)
>> + offset = PMC_WAKE2_MASK;
>> + else
>> + offset = PMC_WAKE_MASK;
>> +
>> + value = tegra_pmc_readl(pmc, offset);
>> +
>> + if (on)
>> + value |= 1 << bit;
>> + else
>> + value &= ~(1 << bit);
>> +
>> + tegra_pmc_writel(pmc, value, offset);
>
> Why the latching is done *before* writing into the WAKE registers? What
> it is latching then?

I'm looking at the TRM doc and it says that latching should be done
*after* writing to the WAKE_MASK / LEVEL registers.

Secondly it says that it's enough to do:

value = tegra_pmc_readl(pmc, PMC_CNTRL);
value |= PMC_CNTRL_LATCH_WAKEUPS;
tegra_pmc_writel(pmc, value, PMC_CNTRL);

in order to latch. There is no need for the delay and to remove the
"LATCHWAKE_EN" bit, it should be a oneshot action.

>> + return 0;
>> +}
>> +
>> static int tegra186_pmc_irq_set_wake(struct irq_data *data, unsigned int on)
>> {
>> struct tegra_pmc *pmc = irq_data_get_irq_chip_data(data);
>> @@ -1954,6 +2014,49 @@ static int tegra186_pmc_irq_set_wake(struct irq_data *data, unsigned int on)
>> return 0;
>> }
>>
>> +static int tegra210_pmc_irq_set_type(struct irq_data *data, unsigned int type)
>> +{
>> + struct tegra_pmc *pmc = irq_data_get_irq_chip_data(data);
>> + unsigned int offset, bit;
>> + u32 value;
>> +
>> + if (data->hwirq == ULONG_MAX)
>> + return 0;
>> +
>> + offset = data->hwirq / 32;
>> + bit = data->hwirq % 32;
>> +
>> + if (data->hwirq >= 32)
>> + offset = PMC_WAKE2_LEVEL;
>> + else
>> + offset = PMC_WAKE_LEVEL;
>> +
>> + value = tegra_pmc_readl(pmc, offset);
>> +
>> + switch (type) {
>> + case IRQ_TYPE_EDGE_RISING:
>> + case IRQ_TYPE_LEVEL_HIGH:
>> + value |= 1 << bit;
>> + break;
>> +
>> + case IRQ_TYPE_EDGE_FALLING:
>> + case IRQ_TYPE_LEVEL_LOW:
>> + value &= ~(1 << bit);
>> + break;
>> +
>> + case IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING:
>> + value ^= 1 << bit;
>> + break;
>> +
>> + default:
>> + return -EINVAL;
>> + }
>> +
>> + tegra_pmc_writel(pmc, value, offset);
>
> Shouldn't the WAKE_LEVEL be latched as well?
>
>> + return 0;
>> +}
>> +
>> static int tegra186_pmc_irq_set_type(struct irq_data *data, unsigned int type)
>> {
>> struct tegra_pmc *pmc = irq_data_get_irq_chip_data(data);
>> @@ -2540,6 +2643,10 @@ static const struct pinctrl_pin_desc tegra210_pin_descs[] = {
>> TEGRA210_IO_PAD_TABLE(TEGRA_IO_PIN_DESC)
>> };
>>
>> +static const struct tegra_wake_event tegra210_wake_events[] = {
>> + TEGRA_WAKE_IRQ("rtc", 16, 2),
>> +};
>> +
>> static const struct tegra_pmc_soc tegra210_pmc_soc = {
>> .num_powergates = ARRAY_SIZE(tegra210_powergates),
>> .powergates = tegra210_powergates,
>> @@ -2557,10 +2664,14 @@ static const struct tegra_pmc_soc tegra210_pmc_soc = {
>> .regs = &tegra20_pmc_regs,
>> .init = tegra20_pmc_init,
>> .setup_irq_polarity = tegra20_pmc_setup_irq_polarity,
>> + .irq_set_wake = tegra210_pmc_irq_set_wake,
>> + .irq_set_type = tegra210_pmc_irq_set_type,
>> .reset_sources = tegra210_reset_sources,
>> .num_reset_sources = ARRAY_SIZE(tegra210_reset_sources),
>> .reset_levels = NULL,
>> .num_reset_levels = 0,
>> + .num_wake_events = ARRAY_SIZE(tegra210_wake_events),
>> + .wake_events = tegra210_wake_events,
>> };
>>
>> #define TEGRA186_IO_PAD_TABLE(_pad) \
>>
>